Hello, it all started when we played CoD 4 PCW (Competitive) and when spectating him it felt a little laggy. So I downed the graphics and it ran smoothly, but I was curious to see his temps on an OEM PC... I told him to install teamviewer, and when I installed MSI Afterburner to check temps and while idle they're at low 80's and jump to 99C in about 5 mins while in CoD 4, while not even maxing the GPU usage... Any ideas guys? I told him to dust his computer ETC, oh and this is with 100% Fan, its an OEM PC with nothing done to it, except dusting (The guy is a complete noobie in computers)

I do know him IRL so I could visit him and try to make it better but I don't have time this week... Any ideas on that?

Get a case with better airflow if its really small or cramped, dust the GPU, and set up a custom fan profile in Afterburner for your friend... That "should" fix it unless the cooling heatsink itself is not installed correctly, and that's a much more complicated problem.